Use your free time for self-development.
It is surprising how much can be accomplished in a short amount of time. Especially if you have a free 30 minutes regularly, every day, you probably underestimate the benefit that this time could have. There are various pursuits in which you can make major progress on a small investment of spare time.
Personally, almost every week day throughout my 7 years at secondary school, I spent 20-30 minutes before the start of the day practising the piano. This long-term project, during time I would not otherwise have put to use, has given me a large repertoire of major piano works by composers including Chopin, Beethoven and Schubert alongside many others. I even performed the Grieg Piano Concerto – a huge challenge, especially on such little practice – after over a year of focused work during my A Levels at the age of 17.
This goes to show that it is certainly possible to achieve big things without the need to sacrifice anything else. I think that this principle can be applied to any hobby/ interest, so why not pick something that you’d like to learn and give it a go – especially if you don’t believe that it’s possible.